. One of the most important questions raised by the ongoing achievements of the Human Genome Project is how this new biological knowledge - and the powers it confers - will affect our identity and self-understanding as human beings. This book project focuses on one key aspect of this complex issue: exploring the extent to which human identity can be reconciled with deliberate design or partial redesign. The author proposes to shed new light on this question by comparing the debates surrounding two areas of scientific innovation that are not normally associated with each other, but that are in fact deeply related: the enterprise of human genetic intervention and the enterprise of building intelligent machines. Both these enterprises entail "pushing the limits" of traditional concepts of what it means to be human; and both ultimately confront their makers with the same core "family" of questions: What are the defining features of human personhood? To what extent can those features be modified or extended, before human personhood begins to break down? Can some (or all) of those features find embodiment in an entity other than a human being? These kinds of questions are no longer the sole province of science fiction writers, but have been taken up with increasing seriousness by mainstream scientists and technologists, as well as by a wide array of "science watchers" in academia, legislative circles, and the news media. . Through documentary research and interviews, this project aims to deepen our understanding of the history and sociology of the debates surrounding these powerful new technologies, electro-mechanical and biological, that are perceived as destabilizing human identity. The intended audience for the book is a broad one: scientists and technological practitioners interested in the social and cultural reception of their research; legislators and other policymakers with a stake in the governance of science; general educated readers who are concerned about the role of science and technology in shaping our collective future.